A typical quick release mechanism has a cam lever assembly which attaches to a skewer; at the other end of the skewer are threads for an adjusting nut. The assembly is intended to tighten by compression, such as a bicycle wheel in a fork or wheel mounting frame, when the adjusting nut is set and the cam lever is rotated to a closed position. The clamping occurs across the skewer and between the inboard cam lever face and the inboard adjusting nut face.
The amount of rotation is approximately 180 degrees, from an open position to a closed position. The mid-range position of the cam lever is typically the position of rotation of the lever arm as it projects outward in a direction parallel to the skewer axis. The fully closed position is the position of rotation of the cam lever arm where the arm is oriented in a direction perpendicular (which includes substantially perpendicular to) to the skewer axis, and parallel to the clamping face plane. The fully open position is the position of rotation of the cam lever arm where the lever arm is perpendicular to the skewer axis and about 180 degrees rotation from the fully closed position.
As a cam lever is rotated from fully open position to a fully closed position a cam portion of the lever reduces the amount of skewer reaching or spanning between the clamping faces and increases the clamping force.